Recent developments of Light Emitting Diodes (LED) backlights for Liquid Crystal Display (LCD) panel displays in televisions and monitors require driving large arrays of LEDs. In many applications, it is desirable to individually control the brightness level of the LEDs. For optimum performance, high brightness LEDs should be driven by a current source rather than by a voltage source. While present circuits to control the brightness levels do work, it is desirable to Page: 2 reduce the required number of power converters, i.e. more than one LED can be powered from each converter. Furthermore, prior art circuits have several issues relating to slow PWM dimming transitions of the LED current and delays and overshoots in the LED current.
Therefore, a need exists to provide a device and method to overcome the above problem.